Safety door lock



July 26, 1960 Filed Feb. 21, 1956 T. REINER 2,946,213

SAFETY DOOR LOCK 2 Sheets-Sheet 1 INVENTOR. 7%[0002 fif/A/f/Q July 26, 1960 T. REINER 2,946,213

SAFETY DOOR LOCK Filed Feb. 21, 1956 2 Sheets-Sheet 2 9 g .ILZ'Q-J- I l /0/ B I Arryi SAFETY noon LOCK Theodor Reiuer, Munich, Germany, assignor to Koenigsdorfer, Freeport, and Helen Lynch, Franklin Square, NY.

Filed Feb. 21, 1956, Ser. No. 566,998

18 Claims. CI. 70-93 The present invention relates to a door lock having a self-contained guard chain and which selectively permits the door to be partially opened with the guard chain connected or fully opened with the guard chain disconnected.

The guard chain is normally retained in the door jamb and becomes extended when the door is opened with the chain connected. The chain prevents forcible entry by an intruder when the door is partially opened to identify a caller. When the door is opened from the outside by means of a key, the guard chain is automatically disconnected. When the door is opened from the inside by means of a knob or handle, the guard chain may be disconnected to permit the door to be fully opened by turning the knob in one direction or may be connected to hold the door partially closed by turning the knob in the opposite direction.

Patented July 26, 1960 A feature of the invention resides in the provisionof V a safety lock for the guard chain the safety lock being so arranged that if the door is partially opened with the guard chain connected, the chain may not be disconnected until the door is first substantially fully closed and latched, after which the door may be reopened with the guard chain disconnected.

Another feature of the invention resides in the attractive appearance of a door which is equipped with such a lock. The guard chain is normally fully retracted within the door jamb so that it is substantially completely concealed except when the door is unlocked and partially opened with the chain connected, and the body portion of the lock itself is completely recessed into the door like any ordinary lock.

Various objects and other features and advantages of the invention will become apparent upon reading the following specification together with the accompanying drawing forming a part hereof.

Referring to the drawing:

Figure 1 is a perspective view from the outside showing the guard chain partially extended for purposes of illustration with the chain disconnected from the lock, one cover plate of the lock being broken away to show details of construction.

Figure 2 is a fragmentary elevational view showing both look portions in closed position of the look as viewed from the inside.

Figure 3 is a sectional view in elevation taken along the line 3-3 of Fig. 2, looking in the direction of the arrows.

Figure 4 is a fragmentary plan sectional view taken along the line 4-4 of Fig. 2.

Figure 5 is a perspective view looking at a door from the inside and with the guard chain connected so that the door is lockedagainst opening beyond the partially open position illustrated.

Referring to Fig. l, the lock consists of a relatively movable portion Acarried by the door 11 (Fig. 5) and which cooperates with a relatively fixed complementary tively movable lock portion A comprises a vertical plate 10 which is adapted to be mortised into the lateral edge of a door 11 (Fig. 5) the door being supported by hinges 12 located at its right hand side when viewed from the inside.

The lock mechanism is mounted between inner and outer cover plates 14 and 15. Only a small fragment of inner cover plate 15 is shown in Fig. 1, it being understood the plate is provided with the usual openings for guiding and journaling the various moving parts of the lock, where required. The fragment shown is secured by a flat head screw 16 threaded into a stud 17' fixed to the inner cover plate 14. The plate 15 is additionally supported by a stud 19 fixed to plate 14 and one leg of a U- shaped bracket 20 is also fixed to plate 14. The stud 19 and bracket 20 are provided with tapped holes 21 and 22, respectively, for receiving'additional mounting screws (not shown) similar to screw 16. At the lower corner of plate 14 there is fixed a fiat stud 23 provided with a projection 24 which is received in a hole (not shown) in plate 15. A fixed square stud 25 is mounted at the upper corner of plate 14 and its free end is received in a square hole (not shown) in plate 15.

The lock is provided with a bifurcated door latch member designated generally as 27. The door latch 27 comprises upper and lower legs 28 and 29 interconnected by a bridge 30 and each provided with a guide flange 31, 31a, respectively, slidingly received in the vertical plate 10. The legs 28, 29 are provided with individual coplanar sloping surfaces 32 and 33, respectively, which ride over cooperating edges 35 and 36 (Fig. 2) showing part of lock portion B of a strike plate 37 to latch the door 11 closed. The legs 23 and 29 of latch 27 straddle a, guide block 39 fixed to inner plate 14. The guide block 39 projects laterally beyond vertical plate 10 and its projecting end has a rectangular aperture formed therein, this rectangularly apertured portion of guide block 39 defining an integrally formed fixed guard member '40. With the latch 27 fully extended, the'outer ends of legs 28 and 29 are in alignment with the free outer end of guard member 40 as shown in Fig. l. Latch 27 is yieldingly urged outwardly by a helical tension spring 41. One end of spring 41 is anchored to a pin 43 fixed to plate 14. The other end of spring 41 is secured to an upright pin 44 carried by latch 27, the upper end of pin 44 being bent to prevent the end of spring 41 from slipping off. Outward movement of latch 27 is limited by engagement of bridge 30 with the inner side of plate 10, the upright pin 44 being received in slot 45 defined by the legs of the U-shaped bracket 20.

A horizontally extending groove 47 is formed in the guide block 39 and a chain latch member designated genorally as 48 is slidably disposed in this groove. The chain latch member 48 is provided with longitudinally spaced lugs 49 which project inwardly beyond the guide block 39. The outer end of the chain latch member 48 is bevelled to form a sloping surface 50 arranged to ride over a coupling member 51 connected to the free end of the guard chain which is located in portion B of the lock as described in detail below.

Outward-movement of the chain latch member 48 is limited by engagement of the outer end of member 48 with the guard member 40.

The upper leg 28 of latch 27 has a recess 55 defining a shoulder 56 adapted for latch retractive engagement by the upper end of master unlatching lever 53. Master lever 53 is pivoted intermediate its ends on a pivot pin 57 fixed to the rounded free end portion 59 of a lock tumbler plate 60. Master lever 53 is recessed to receive the rounded end 59 of tumbler plate 60, the end 59 being rounded concentrically with respect to pivot pin 57. A helical tension spring 61 yieldingly urges master lever 53 downwardly and in a clockwise direction of rotation as viewed in Fig. 1. A flat leaf spring 62 urges tumbler plate 60 in a clockwise direction as viewed in Fig. 1. One end of tension spring 61 is hooked in an aperture 63 in master lever 53 and the other end is anchored to a fixed pin 64 located below aperture 63 and carried by plate'l l so that helical spring 61 aids leaf spring 62 in urging tumbler plate 60 in a clockwise direction.

' A bolt designated generally as 65 is provided for locking the door 11 so that it may be opened only by means of a key. The bolt comprises an outer end portion 67 of rectangular cross-section which is extensible and re tractable through a complementary aperture formed in vertical plate 10. The other inner end of bolt 65 is slotted and guided for horizontal movement by a fixed pin 68 mounted on plate 14. Pin 68 also carries a series of conventional tumbler plates 69 interposed between tumbler plate 60 and bolt 65, all pivoted on fixed pin 63 along with tumbler plate 6%). The series of plates 69 are all individually urged in a clockwise direction by a corresponding series of leaf springs 71 the outer free ends of which bear upwardly against stud 19. The tumbler plates 69 cooperate in conventional manner with slots of varying idepths cut in the edge of the end of a key which may be inserted in the look through a keyhole 72, When the key slots are of the correct depths, gaps between the juxtaposed ends of projections on each tumbler plate are aligned to permit the passage therebetween of a dog 73 which projects laterally from bolt 65. This type of bolt operating mechanism is conventional in all respects and has therefore not been illustrated in detail.

For operation of the lock from the inside, there is provided a rotary unlatching member designated generally as 75. The rotary member 75 is provided with coaxial, rounded, shallow extensions 76 which are journaled in round holes (not shown) formed in plates 14 and 15 'so that the member 75 is rotatably retained between these plates. A square hole 77 formed in rotary member 75 is adapted toreceive an operating shaft of square crosssection (not shown) on which an inside door knob or handle 79 (Fig. is mounted. Rotary member 75 is provided with vertically aligned feet 36. The feet 80 engage a downwardly extending straight free end portion 81-of a spiral torsion spring 83. The upper or inside end of spring '83 is wrapped around and secured to the square stud 25, the straight portion 81 being pressed against the feet 80 so that the rotary member 75 is yieldingly urged to assume the position shown in Fig. l, but maybe angularly displaced therefrom in either direction by rotation of the door knob 79.

The rotary member 75 comprises an upwardly extendingleg 84 having a free end which is adapted to engage a downwardly extending projection 85 formed on the inner end of leg 28 of latch 27. Thus, when the member 75 is rocked in a counterclockwise direction as viewed in Pig. 1 (clockwise rotation of door knob 79) latch 27 is drawn to the left. Master lever 53 remains undisturbed, however, because of the width oi the recess 55, the tip of chain latch 48 being held pressed against t-heinside of guard member 4!} by the action of tension spring 61 on master lever 53.

Rotary member 75 also carries a pair of integrally formed downwardly depending ears 87. One end of a hooked lever -88 is fastened between the cars 87 by a pivot pin 90. The other end of the hook of lever 88 is provided with a projection or hook 91 which is engageable with the edge of master lever 53. When rotary member 75 isztur-ned in clockwise direction as viewed in Fig. l (counterclockwise rotation of door knob 79), the hook lever 88 is drawn leftwardly causing master lever 53 to rotate in .a counterclockwise direction on pivot pin 57, thereby drawing chain latch 48 to the left. At the same time, the upperend of master lever 53 engages the shoulider 56 of upper latch leg 28 27 to the left.

The lower end 92 of the master lever 53 is adapted to be engaged by a key when bolt 65 is fully retracted, but is held out of the way whenever the bolt is extended. For this purpose, tumbler plate 60 is provided with a shallow slot 94 in which'dog 73 is shown engaged in Fig. 1, with the bolt 65 fully retracted. In this position, the tumbler plate 60 is held in a relatively counterclockwise raised angular position so that pivot pin 57 is lifted and the lower end 92 of master lever 53 is positioned to be acted upon by turning a key inserted through keyhole 72. When the bolt 65 is either half way or fully extended, the dog '73 is received in either of two deep slots 95 in the tumbler plate 60.. Spring 61 then moves master lever 53 downwardly as permitted by engagement of dog 73 in either of the two deeper slots 95 and the correspondingly greater clockwise rotation of tumbler plate 60 after it is released by the end of the key. This places the lower end 92 of master lever 53 in the position indicated by dotted lines in Fig. 1 out of reach of the key during extension or retraction of bolt 65.

However, after the bolt 65 has been fully retracted and the tumbler plate 6% has returned to the position shown in Fig. 1, further rotation of the key in the unlocking direction will press on the lower end of master lever 53 (now in the position shown in full lines in Fig. l) to swing lever 53 counterclockwise about pivot pin 57 and thus to withdraw both the door latch .37 and the chain latch 43. When some other type of lock mechanism is used for operation of the bolt 65, the arrangement illustrated for preventing operation of the master lever 53 during extension or retraction of bolt 65 may be readily adapted to such other lock mechanism, particularly because the master lever 53 may be moved longitudinally by reason of the mobility of pivot pin 57. The projection 91 on hook lever 88 does not interfere with this longitudinal movement. Since engagement be and draws the door latch tween projection 91 and master lever 53 is useful only when the bolt 65 is fully retracted, the master lever 53 may be moved longitudinally in either direction by any convenient means to prevent interference with the keyoperated portion of the lock during extension or retraction of the bolt.

The relatively movable portion A of the lock, thus far described in detail, is mortised in the door 11 so that it is comparatively inconspicuous. The relatively fixed complementary lock portion B comprises an angle member 96 with two vertically elongated mutually perpendicular flanges or legs, the from one of which extends parallel to the inside surface of the door 1]. when the door is closed and forms the strike plate 37 for door latch 27, referred to above. a side flange 97 confronts and extends parallel to the edge of the door 11 when the door is closed. The angle 96 is mortised into the door jamb 98 (Fig. 5) and is secured by screws (not shown) inserted through mounting holes 99 (Fig. 1). The side flange 97 of angle 96 has a rectangular aperture 100 formed therein for receiving the outer end 67 of bolt 65 when the door 11 is bolted closed. The angle 96 also has a complex opening designated generally as 101 formed therein. Opening 191 comprises a front portion 191a formed in strike plate flange 3'7 and a lateral portion ltllb of generally rectangular shape formed in the side flange 97, the portions Mil-a and lllj'b communicating with each other through the corner of angle 96 which is cut away for this purpose. The .door latch 27 is received in the lateral portion 161-19 which is vertically elongated to define the door latch retainingedges 35 and 36 of, strike plate flange 37. The cut away in the corner of angle 96 is sufficiently long-tapermit the passage therethrough of the guard member 40 for chain latch ,48 and the front portion 101a of aperture 101 is of sm'fieient size to permit passage ofs ard member 40 ireely ztherethrb lgh- Th fronttn rti n 101a of aperture 101 is laterally free passage of coupling member 51 through the strike plate flange 37.

A chain guide designated generally as 102 is secured to the rear of strike plate flange 37 by mounting ears 103. The door jamb 98 is appropriately recessed to accommodate a guard chain 105 therein enclosed by angle 96, together with chain guide 102. The chain 105 is yieldingly drawn into the door jamb 98 by a helical tension spring 106. The lower end of spring 106 is anchored to a pin 107 fixed on angle 96. The other end of spring 106 is connected to a stop pin 109 disposed at the inner end of guard chain 105. The coupling member 51 is secured to the outerend of chain 105 for engagement with chain latch 48. Intermediate its ends, the guard chain 105 is formed by a series of flat link plates 110 with rounded ends pivotally interconnected by a series of pivot pins 111. The chain guide 102 is provided with a rounded guide surface 113 so that the chain 105 may move freely and smoothly in or out of the door jamo through a rectangular aperture 114 in guide 102. Outward movement of chain 105 is limited by stop pin 109 which is provided with enlarged heads so that it is too long to pass through aperture 114. Inward movement is limited by coupling member 51 which is also too large in the vertical direction to pass through aperture 114. The rectangular shape of aperture 114 prevents the chain 105 -from tuming or twisting.

The coupling member 51 is of symmetrical construction so that it may be assembled on the outer end of chain 105 in either of two possible positions. The coupling member 51 comprises a latching ear 115 and a guide ear 117. The latching ear 115 has a rectangular aperture 118 formed therein for receiving the end of chain latch 48. A similar aperture 119, formed in ear 117, is provided for purposes of symmetry. The guide car 117 is held against lateral movement toward the left as viewed in Fig. 4 by engagement with side wall 120 of chain guide 102. The latching ear 115 is rounded at its outer end as indicated at 121 to form a strike surface facilitating latching engagement with chain latch 48 as the door 11 is closed. The spaced ears 115 and 117 define therebetween a slot 122 in which the outer end of guard member 40 is received and held when the door is closed or is opened with the chain connected.

A shallow rectangular notch 123 is formed in the chain latch 48 and serves as a safety lock for the purpose of preventing the chain latch 48 from being withdrawn from engagement with the edge of aperture 118 of coupling member 51. Because the tension spring 106 urges the edge of aperture 118 forcibly into the rectangular notch 123, it is impossible to withdraw chain latch 48 from coupling engagement with coupling member 51, whenever the door 11 is opened with the guard chain 105 connected to chain latch 48. Under these conditions, latch 48 can be retracted no further than a sufiicient distance to press latching car 115 of coupling member 51 against vertical plate 10. Before chain latch 48 can be withdrawn from aperture 118, the door 11 must first be closed to a suificient extent so that coupling member 51 becomes seated against chain guide 102 and chain latch 48 has moved with respect to coupling member by a distance slightly greater than the depth of rectangular notch 123. When this condition has been attained, the door latch 27 will engage and hold the door closed in response to a very slight further closing movement of door 11. The momentum of closing movement, if suificient to carry the door to the position where it is possible to release chain latch 48- will invariably be sufiicient to permit the door latch 27 to take hold so that it is efiectively necessary to close the door completely before the guard chain may be released.

It will also be apparent, that with the guard chain conextended at 1010 to permit nected, the coupling member 51 cannot be disconnected from the outside by an intruder. The end of guard member 40, which enters slot 122 between ears 115 and 117 of coupling member 51, prevents access to chain latch 48 by a person reaching through the partially open door. The safety lock provided by notch 123 further prevents release of the guard chain by an unauthorized person.

Briefly summarized, in operation, the door 11 may selectively be opened from the inside with or without the guard chain 105 connected by turning the door knob 79 in a clockwise or counterclockwise direction, respectively. The door may be bolted in the usual manner by means of a key. When the key is used to open the door it may operate to retract the bolt. and turning of the key in the unlocking direction with the bolt in its fully retracted position will simultaneously retract both the door latch 27 and the chain latch 48 so that the door opens freely.

While I have shown what I believe to be the best embodiment of my invention, it will be apparent to those skilled in the art that many modifications may be made in the specific embodiment shown and described without departing from the spirit and scope of the invention as defined in the appended claims.

What I claim is:

1. A door lock of the class described comprising, in combination: a relatively movable portion adapted to be mortised in a door; a relatively stationary portion adapted to'be mortised in a door jamb for cooperation with said movable portion; chain guide means included in said stationary portion; a guard chain freely movable through said guide means; retractile means yieldingly urging said chain inwardly into said stationary portion; stop means for limiting outward movement of said chain; coupling means fixed to the outer end of said chain; strike plate means having a recess formed therein, said recess permitting passage of said coupling means therethrough, said guide means being disposed behind said recess and providing a seat within said door jamb for said coupling means; outwardly spring-pressed door latch means and outwardly spring-pressed chain latch means included in said movable portion, said door latch means being adapted for latcln'ng engagement with said strike plate means and said chain latch means being arranged for passage through said recess for latching engagement with said coupling means; and manually operable unlatching means included in said movable portion and selectively actuable either to retract said door latch means alone for limiting opening of said door or to retract both said door latch means and said chain latch means together for permitting said door to be fully opened.

2. A lock according to claim 1, further comprising 7 safety lock means included partially in said coupling means and partially in said chain latch means, said safety lock means providing two cooperating interlocking members for holding said coupling means and said chain latch means locked together when said guard chain is moved outwardly, whereby release of said guard chain when said guard chain is in an extended condition is prevented.

3. A look according to claim 1, wherein said chain latch means has a recess formed therein in which a cooperating portion of said coupling means is received and held in said recess by said retractile means With'said chain extended, said recess, when said cooperating portion is received therein, preventing retraction of said chain latchmeans, said chain guide means, with said door closed, holding said couplingmeans with said cooperating portion thereof maintained out of said recess so as to permit retraction of said chain latch means.

4. A lock according to claim 1, further comprising key-operable locking means comprised in said movable portion, said key-operable means including a bolt extensible and retractable by means of a key to lock and unlock said door, said unlatching means including a portion actuable by said key when said bolt is fully retracted, said last-named portion being actuable by said key to unlatch both said chain latch means and said door latch means simultaneously.

5. A look according to claim 1, wherein said chain latch means comprises an inwardly and outwardly movable chain latch member having a sloping surface at its outer end, and in which said coupling means comprises a coupling member having an aperture formed therein for receiving said chain latch member, said coupling member having a rounded strike surface formed at its outer end for forcing said chain latch member inwardly by engagement with said sloping surface, whereby said chain latch member may reach and enter said receiving aperture.

6. A lock according to claim 5, further comprising a guide block member included in said movable lock portion and having an aperture formed therein at its outer end, said apertured portion of said guide block member defining an outwardly projecting guard member which is arranged for free passage through said recess in said strike plate means as said door is opened and closed, said sloping outer end portion of said chain latch member in the outward position of the latter being disposed in said guide block member aperture and said coupling member comprising a portion including said chain latch member receiving aperture which enters said guide block member aperture for latching engagement with said chain latch member.

7. A lock according to claim 6, wherein said chain latch member, in its outward position, extends across said aperture in said guide block member.

8. A lock according to claim 6, wherein said chain latch member is slidably disposed in a groove formed in said guide block member. I

9. A lock according to claim 6, wherein said guide block member is rectangular and in which said door latch means includes a door latch member which is bifurcated to provide spaced parallel leg portions slidable along opposite sides of said guide block member.

10. A lock according to claim 9, wherein said guide block member has a groove formed therein extending parallel to and intermediate said opposite sides, said chain latch member being slidably disposed in said groove intermediate said leg portions of said door latch member.

11. A lock according to claim 1, further comprising key-operable locking means comprised. in said movable portion, said key-operable means including a bolt extensible and retractable by means of a key to lock and unlock said door, said unlatching means including a master lever simultaneously engageable with said door latch means, said chain latch means and. said key-operable means, said master lever being actuable by said key for retracting said door latch means and said chain latch means together with said bolt in its retracted position.

12. A lock according to claim 11 in which said master lever is longitudinally movable, said master lever being actuable by said key only in a predetermined position of said longitudinal movement, said key-operable means further comprising means for displacing said master lever longitudinally from said predetermined position when said bolt is extended to prevent actuation thereof by said key and returning said master lever to said predetermined position for actuation by said key when said bolt is retracted.

13. A lock according to claim 12, wherein said keyoperable means includes'a pivotally mounted key-actuable tumbler plate engageable by said bolt and which is angularly displaced duringmovement of said boltjas said bolt is extended and retracted, said master lever being pivotally connected to said tumbler plate for causing said longitudinal movement, movement of said master lever during actaution thereof by said key being an angular displacement of said master lever about its pivotal connection to said tumbler plate.

14. A look according to claim 11, further comprising a rectangular guide block member included in said movable lock portion, said door latch means comprising a latch member having spaced parallel leg portions slidably engaging opposite sides of said guide block member, said guide block member having a groove formed in a face thereof, said groove extending parallel to and intermediate said opposite sides, said chain latch means comprising. an elongated chain latch member slidably disposed in said groove, said master lever extending across the grooved face of said guide block member to be engageable with said chain latch member for retraction of said chain latch means, said master lever further being engageable with said door latch member for retraction of said door latch means.

15. A lock according to claim 14, further comprising an extension formed on said guide block member, said extension having an aperture formed therein whereby said extension defines a guard member for said chain latch member, said chain latch member, when extended, extending completely across said aperture in said extension and wherein said coupling means comprises a coupling member having a portion which enters into said aperture in said extension for coupling engagement with said chain latch member, said lock additionally comprising spring means connected to said master lever for urging said chain latch member into engagement with said coupling member. 7

16. A lock. according to claim 1, wherein said unlatching means comprises a master lever engaging both said door latch means and said chain latch means.

17. A lock according to claim 1, wherein said door latch means comprises an inwardly and outwardly slidable door latch member, and wherein said chain latch means comprises an inwardly and outwardly slidable chain latch member movable parallel to said door latch member, and in which said unlaching means comprises a master lever simultaneously engageable with both of said latch members, said master lever and said door latch member being mutually arranged to permit inward movement of said door latch member independently of said master lever.

18. A look according to claim 17, wherein said unlatching means comprises a rotatable member turnable in either direction from a normal position, said rotatable member comprising two projecting arms, one of said arms being adapted to retract said door latch member independently of said chain latch member when said rotary member is turned in one direction, the other of said arms being connected with said master lever for retracting both of said latch members simultaneously when said rotatable member is turned in the other direc tion.

References -Cited in the fileof this patent UNITED STATES PATENTS 1,988,049 Reiner Ian. 15, 1935 2,062,020 Engel Nov. 24, 1936 2,369,136 Chambers et al Feb. 13, 1945 2,407,900 Paul Sept. 17, 1946 

